In the field of X-ray detection, it has been a long standing goal of practitioners to improve upon the images which can be created by "reading" the X-rays projected through the target being scrutinized. The basic aim is to increase the image resolution while at the same time to decrease the amount of X-radiation which has to be passed through the target. This is especially important in medical applications, where prolonged exposure to X-radiation will inflict damage to the tissues which it penetrates. The current revolution in digital processing has afforded techniques for effectively and efficiently using computers to create better X-ray images.
Currently, it is known in the art to use "intensifying screens" to begin the conversion of the X-radiation passing through the target into a form of information suitable for analysis. Such screens are commonly made of a material which will scintillate visible wavelength radiation upon being bombarded by X-radiation. For each X-ray photon striking the material, a larger number of light photons are created. This, in effect, establishes a very basic X-ray conversion and amplifier mechanism.
While such intensifying screens do act to reduce the radiation risk to which a patient or X-ray source operator is exposed by reducing the dosage required to obtain an acceptable X-ray image, such screens have an inherent effect on the resolution achieved in the final image. The visible light photons produced in a screen emanate from the bombardment-conversion event in random directions, exiting the screen in directions other than that of the incident X-ray which produced the visible wavelength photons. In other words, a "scatter effect" is produced which degrades the final image.
Recent patents have suggested different approaches to the construction of such screens in order to improve their performance and thereby produce more acceptable final images. U.S. Pat. Nos. 3,041,456 and 3,643,092, and 3,936,645, each offer cellularized-type screens which partially intensify the radiation to be converted to a usable data format. These known structures use devices to limit the paths taken by the visible photons produced in order to reduce the scattered luminescent radiation diffusing from the screen. Although these intensifying screens reduce the inherent scattering effect of the visible radiation produced by the impinging X-radiation, a certain quantity of the effect remains and, therefore, still affects the resolution of the final image produced.
Therefore, it is a primary object of the present invention to improve images created by X-radiology techniques.
Another object of the present invention is to efficiently convert X-radiation to visible radiation.
It is another object of the present invention to utilize the large number of light photons created in X-radiation sensitive phosphorescent crystals by each striking X-ray photon irregardless of its initial angle of projection when created.
It is a further object of the present invention to reduce patient dosage of X-rays in a medical environment.